Display screen or portion thereof with an animated graphical user interface



FIG. 1 is a front view of a display screen or portion thereof with animated graphical user interface showing a first image which is part of a sequence showing our new design; and,

FIG. 2 is a second image thereof.

The appearance of the animated images sequentially transition between the images shown in each respective set of front views of the animated graphical user interfaces as shown in FIGS. 1 through 2. The process or period in which one image transitions to another forms no part of the claimed design.

The outermost, circular dashed lines showing a display screen or a portion thereof are included for the purpose of illustrating portions of the article of manufacture forming no part of the claimed design. The other dashed lines in the drawings are included for the purpose of illustrating portions of the graphical user interface that form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with an animated graphical user interface, as shown and described. 